Document
WM7211E
Top Port Digital Silicon Microphone
DESCRIPTION
The WM7211 is a low-profile silicon digital microphone. It offers high Signal-to-Noise Ratio (SNR) and low power consumption and is suited to a wide variety of consumer applications.
The WM7211 incorporates Cirrus’s proprietary CMOS/MEMS membrane technology, offering high reliability and high performance in a miniature, low-profile package. The WM7211 is designed to withstand the high temperatures associated with automated flow solder assembly processes. (Note that conventional microphones can be damaged by this process.)
The WM7211 incorporates a high performance ADC, which outputs a single-bit data stream using Pulse Density Modulation (PDM) encoding. The WM7211 supports selectable left/right channel assignment for a two-channel digital microphone interface, enabling efficient connection of multiple microphones in stereo/array configurations.
The WM7211 offers tight tolerance on the microphone sensitivity, giving reduced variation between parts. This removes the need for in-line production calibration of partto-part microphone variations.
FEATURES
High SNR (61dB) Low variation in sensitivity (±1dB tolerance) Low current consumption
- 2μA (Sleep) - 735μA (Normal operation) PDM digital audio output Stereo/array operation Proprietary ADC technology - Reduced clock jitter sensitivity - Low noise floor - Stable in overload condition Top Port LGA Package 1.64V to 3.7V supply
APPLICATIONS
Mobile telephone handsets Portable computers Portable media players Digital still cameras Digital video cameras Bluetooth headsets Portable navigation devices
BLOCK DIAGRAM
WM7211
VDD
CHARGE PUMP
CONTROL
3D VIEW
CLK DAT LRSEL
CMOS MEMS Transducer
AMP
ADC
GND
4.00mm x 3.00mm x 1.00mm LGA package
http://www.cirrus.com
Copyright Cirrus Logic, Inc., 2011–2016 (All Rights Reserved)
Rev 4.0 MAR ‘16
TABLE OF CONTENTS
WM7211E
DESCRIPTION................................................................................................................ 1 FEATURES ..................................................................................................................... 1 APPLICATIONS.............................................................................................................. 1 BLOCK DIAGRAM ......................................................................................................... 1 3D VIEW ......................................................................................................................... 1 TABLE OF CONTENTS.................................................................................................. 2 PIN CONFIGURATION ................................................................................................... 3 PIN DESCRIPTION......................................................................................................... 3 ORDERING INFORMATION........................................................................................... 3 ABSOLUTE MAXIMUM RATINGS ................................................................................. 4 IMPORTANT ASSEMBLY GUIDELINES ....................................................................... 4 RECOMMENDED OPERATING CONDITIONS.............................................................. 4 ACOUSTIC AND ELECTRICAL CHARACTERISTICS .................................................. 5
TERMINOLOGY .........................................................................................................................6
AUDIO INTERFACE TIMING .....................................................................................................7
TYPICAL PERFORMANCE ............................................................................................ 8 APPLICATIONS INFORMATION ................................................................................... 9
RECOMMENDED EXTERNAL COMPONENTS ........................................................................9
OPTIMISED SYSTEM RF DESIGN ...........................................................................................9
CONNECTION TO A CIRRUS AUDIO CODEC .........................................................................9
PCB LAND PATTERN AND PASTE STENCIL ........................................................................10
PACKAGE DIMENSIONS............................................................................................. 11 IMPORTANT NOTICE .................................................................................................. 12 REVISION HISTORY .................................................................................................... 13
2 Rev 4.0
PIN CONFIGURATION
WM7211E
32
41
5 Top View
PIN DESCRIPTION
PIN NAME
1 VDD 2 LRSEL
TYPE
Supply Digital Input
3 CLK Digital Input
4
DAT
Digital Output
5 GND
Supply
DESCRIPTION
Power Supply Channel Select 0 = Data output following falling CLK .